Update gson dep to 2.8.9

Author: cowtowncoder

pom.xml

@@ -142,7 +142,7 @@
       <dependency>
         <groupId>com.google.code.gson</groupId>
         <artifactId>gson</artifactId>
-        <version>2.8.6</version>
+        <version>2.8.9</version>
       </dependency>
 
       <dependency>